gtk-ng/wayland: allow more quick terminal configs (#8484)

We should at least be on par with what Kitty's panels could do in terms
of customization

src/apprt/gtk-ng/winproto/wayland.zig

@@ -114,11 +114,13 @@ pub const App = struct {
             return false;
         }
 
-        if (self.context.xdg_wm_dialog_present and layer_shell.getLibraryVersion().order(.{
+        if (self.context.xdg_wm_dialog_present and
+            layer_shell.getLibraryVersion().order(.{
                 .major = 1,
                 .minor = 0,
                 .patch = 4,
-        }) == .lt) {
+            }) == .lt)
+        {
             log.warn("the version of gtk4-layer-shell installed on your system is too old (must be 1.0.4 or newer); disabling quick terminal", .{});
             return false;
         }
@@ -128,10 +130,7 @@ pub const App = struct {
 
     pub fn initQuickTerminal(_: *App, apprt_window: *ApprtWindow) !void {
         const window = apprt_window.as(gtk.Window);
-
         layer_shell.initForWindow(window);
-        layer_shell.setLayer(window, .top);
-        layer_shell.setNamespace(window, "ghostty-quick-terminal");
     }
 
     fn getInterfaceType(comptime field: std.builtin.Type.StructField) ?type {
@@ -411,6 +410,14 @@ pub const Window = struct {
         else
             return;
 
+        layer_shell.setLayer(window, switch (config.@"gtk-quick-terminal-layer") {
+            .overlay => .overlay,
+            .top => .top,
+            .bottom => .bottom,
+            .background => .background,
+        });
+        layer_shell.setNamespace(window, config.@"gtk-quick-terminal-namespace");
+
         layer_shell.setKeyboardMode(
             window,
             switch (config.@"quick-terminal-keyboard-interactivity") {

src/config/Config.zig

@@ -2144,6 +2144,44 @@ keybind: Keybinds = .{},
 /// terminal would be half a screen tall, and 500 pixels wide.
 @"quick-terminal-size": QuickTerminalSize = .{},
 
+/// The layer of the quick terminal window. The higher the layer,
+/// the more windows the quick terminal may conceal.
+///
+/// Valid values are:
+///
+///  * `overlay`
+///
+///    The quick terminal appears in front of all windows.
+///
+///  * `top` (default)
+///
+///    The quick terminal appears in front of normal windows but behind
+///    fullscreen overlays like lock screens.
+///
+///  * `bottom`
+///
+///    The quick terminal appears behind normal windows but in front of
+///    wallpapers and other windows in the background layer.
+///
+///  * `background`
+///
+///    The quick terminal appears behind all windows.
+///
+/// GTK Wayland only.
+///
+/// Available since: 1.2.0
+@"gtk-quick-terminal-layer": QuickTerminalLayer = .top,
+/// The namespace for the quick terminal window.
+///
+/// This is an identifier that is used by the Wayland compositor and/or
+/// scripts to determine the type of layer surfaces and to possibly apply
+/// unique effects.
+///
+/// GTK Wayland only.
+///
+/// Available since: 1.2.0
+@"gtk-quick-terminal-namespace": [:0]const u8 = "ghostty-quick-terminal",
+
 /// The screen where the quick terminal should show up.
 ///
 /// Valid values are:
@@ -7202,6 +7240,14 @@ pub const QuickTerminalPosition = enum {
     center,
 };
 
+/// See quick-terminal-layer
+pub const QuickTerminalLayer = enum {
+    overlay,
+    top,
+    bottom,
+    background,
+};
+
 /// See quick-terminal-size
 pub const QuickTerminalSize = struct {
     primary: ?Size = null,